Flybuck, Coupled Inductor and Buck topologies

I'm trying to understand how TI series of flybuck converters differ from standard flyback.

Both the tight load regulation provided by the flybuck, versus a flyback with a secondary winding for regulation and the option to use the primary coil as a regulated non isolated supply would prove very usefull, for example in a half bridge IGBT gate driver supply.

From the datasheets, Its not clear whenever the flybuck is just a buck with a synchronous rectifier, or a flyback with the built in zenner diodes to clamp the transformer reverse voltage, or perhaps something completelly different. Can the topology be implemented using a standard buck or flyback converter, where a dedicated flybuck controller is not available, such as an offline converter?

Can a flyback and Flybuck transformers be interchanged or is there a specific requirement for each?

Thanks